Vehicles can be equipped to operate in both autonomous and occupant piloted mode. Vehicles can be equipped with computing devices, networks, sensors and controllers to acquire information regarding the vehicle's environment and to operate the vehicle based on the information. Safe and comfortable operation of the vehicle can depend upon acquiring accurate and timely information regarding the vehicle's location. Therefore, it is important that vehicle sensors provide the most accurate data possible concerning the vehicle's location. For example, safe and comfortable operation of the vehicle would be enhanced by addressing the problem of acquiring accurate and timely information regarding the location of the vehicle with respect to a map and therefore with respect to roadways and objects while the vehicle is being operated on a roadway.